Design Build (DB) vs Design Bid Build/DBB
Traditionally, Owners, Developers and Municipalities have utilized the design-bid-build method of procuring design and construction services for most of their capital outlay projects. This approach allows the Owner/Decision Maker to determine the exact product before it begins construction. Projects are not bid on by construction contractors until working drawings are completed by a separate architect-engineering firm and the Owner Client usually requires multiple General Contractor Bids to determine the lowest bid or proposal per the defined construction documents.
In the traditional design-bid-build process, preliminary plans, working drawings, and construction are all separate phases. Funds are not normally committed to the project unless there is a strong assurance that the project can be built within a predetermined cost and a fixed duration over time. Consequently, most large design-bid-build projects are budgeted in several phases over two to three years (sometimes longer).
In design-build projects, design work is performed by the same entity that constructs the project, and the design-build contract award is made in a lump sum. Consequently, there are no separate phases—or appropriations—for preliminary plans, working drawings, and construction. The client is responsible for providing a project definition, which the design-build firm uses as the basis for its bid. The advantage of the design-build approach is that the project delivery team has single-point responsibility for the project as only one contract is negotiated. Not only does this help expedite construction time frames, but may reduce the number of change orders. Another advantage of design-build is that the total project duration can be reduced and thereby save the client construction loan dollars in interest. This allows the facility to be in operation sooner, which means a value added benefit. The economy has given momentum to this project delivery method over other more traditional ones.